A large percentage of the adult United States population is overweight or is prone to be overweight. Bookstores carry entire sections devoted to books which their readers hope will provide an easy solution to their weight problems. Dietetic foods, drugs, weight reducing programs, machines and treatments abound, and millions of dollars are spent in an effort by overweight persons to solve their weight problems.
Competent medical specialists who have studied the problems of obesity generally are convinced, however, that the only effective method of controlling weight is to balance the intake of energy in the form of food with the expenditure of energy in the form of activity. Whenever an imbalance exists in the form of a greater energy intake than is expended, an increase in weight results. In theory, the maintenance of a balanced caloric intake/expenditure should be easily established. Readily available charts have been published which provide accurate data on the caloric content of all types of foods and beverages. In addition, caloric expenditures of a wide range of human activities from sleep through strenuous exercise have been measured and charted. Many thousands of individuals have succeeded in achieving their desired weight and maintaining that weight by balancing their caloric intake with expenditure. Many persons carry calorie counter charts with them wherever they go to limit their caloric intake in a given day to some maximum amount which they or their doctors have determined should not be exceeded if a weight loss is to be attained or maintenance of a given weight is to be established.
Some persons appear to have a built-in ability to strike the right balance between caloric intake and expenditure. For a large number of persons however, perhaps the vast majority, it is necessary to keep a record of the calories consumed and the activities performed and the duration of such performance in order to maintain an effective caloric balance. To be truly effective, data of this type must be accurate and must be continuously accounted for 24 hours of every day.
Anyone who has observed a person on a diet is well aware of the inconvenience of the collection and recording of such data and performing the addition, subtraction and multiplication required to produce meaningful information relative to caloric intake, expenditure, and remaining unexpended calories. This inconvenience most likely is responsible for the fact that only a relatively small number of persons use this technique, even though it is an effective solution to the widespread problem of calorie control.
Solid-state battery-powered electronic wristwatches utilizing digital displays in the form of light-emitting diodes or liquid crystals are enjoying increasing popularity. A typical watch of this type is disclosed in U.S. Pat. No. 3,803,827 to Dennis A. Roberts, issued Apr. 16, 1974. The electronic wristwatch of that patent is provided with a master time reference in the form of a high frequency oscillator connected to the watch display through suitable divider circuits to provide indicia of the time on demand by operation of a switch to energize a plurality of light-emitting diodes. The time computer portion of the watch circuit continuously keeps the time although it is only displayed upon demand. The display and the driver circuits for the display also are shared by a calendar calculating circuit which may be coupled to the display diodes upon demand by operation of a calendar display switch.
Digital electronic wristwatches have been combined in a single housing with a miniature calculator in which the calculator output display also shares the display elements which are used to display the time or calendar information. Thus, techniques presently are available in improved electronic watch constructions which permit sharing of the time display elements for other purposes.
It is desirable to incorporate a calorie counter into an electronic wristwatch which will enable the user to readily enter caloric intake information into the wristwatch/calorie calculator, determine a caloric rate expenditure, and have readily available on a continuous basis data indicative of the excess of calorie intake over calorie expenditures. This then would provide the user, at any time, the data necessary to see the state of his calorie intake/expenditure account; so that he can modify his future calorie intake or his activity or both to achieve the results he wants with his own diet program.